JP3379998B2 - Method for manufacturing solid electrolytic capacitor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a solid electrolytic capacitor using a film made of a conductive composition containing polyaniline as a solid electrolyte.

[0002]

2. Description of the Related Art An electrolytic capacitor is a capacitor in which an insulating coating is formed on the surface of a metal foil of aluminum or tantalum by electrolytic oxidation and the insulating coating is used as a dielectric. Recent major technical requirements for electrolytic capacitors include miniaturization, low impedance accompanying high frequency circuits, high reliability, long life, and low cost. To meet these demands, research has been conducted in the direction of solidifying an electrolyte of an electrolytic capacitor which has been a liquid, and as such a solid electrolyte, for example, polypyrrole, polythiophene, polyfuran, polyaniline, etc. Conductive polymers have been proposed.

More specifically, for example, JP-A-63-17
No. 3313 discloses that a dielectric oxide film is formed on a film-forming metal, polypyrrole is deposited on the dielectric oxide film by chemical oxidative polymerization of pyrrole, and this is used as a conductive layer. , Pyrrole is electrolytically polymerized, and a conductive polymer composed of the polypyrrole is laminated as a solid electrolyte. In addition, JP-A-1-253
Similarly, Japanese Patent Laid-Open No. 226 describes that a conductive layer made of manganese dioxide is formed on a dielectric film, and polypyrrole or polythiophene is laminated thereon by electrolytic polymerization to form a solid electrolyte.

However, in all of these methods, it is necessary to laminate polypyrrole or the like on the dielectric film that is not a conductor by an electrolytic reaction, which is problematic. That is, a chemical oxidation polymerization film layer or a manganese dioxide layer must be provided on the dielectric film as a conductive layer to serve as an electrode for electrolytic polymerization, and electrolytic polymerization can be performed only in this way.

On the other hand, in Japanese Patent Laid-Open No. 3-35516,
A method has been proposed in which polyaniline in a solution state is applied onto a dielectric film to form a film, and then the polyaniline film is dipped in a solution of a protonic acid to perform a doping treatment. According to this method, a conductive polyaniline film can be formed on the dielectric film by a simple means without providing an electrode, which is advantageous in terms of manufacturing efficiency and cost.

[0006]

However, in the doping treatment of the polyaniline film in the protic acid solution,
Requires hours to days. As described above, it is not preferable that the doping process takes a long time from the viewpoint of manufacturing efficiency, and the protonic acid may penetrate from the polyaniline film and corrode the film forming metal that is the anode of the solid electrolytic capacitor. There is also.

The present invention has been made in order to solve the above-mentioned problems in the production of a solid electrolytic capacitor using a conventional conductive polyaniline film as a solid electrolyte. It is possible to form a solid electrolytic capacitor using a conductive polyaniline film as a solid electrolyte by solving the disadvantage of the manufacturing process, which requires a long time for the doping process described above, by forming the solid electrolytic capacitor on the dielectric film by various methods. The object is to provide a process which can be manufactured well.

[0008]

According to the present invention, a dielectric oxide film is formed on a film-forming metal, and a film made of a conductive organic polymer composition containing polyaniline is formed on the dielectric oxide film as a solid electrolyte. In the method for producing a solid electrolytic capacitor having

[0009]

[Chemical 2]

[0010] consists represented imino -p- phenylene structural unit, a solution composition comprising polyaniline and protonic acid salt which is soluble in an organic solvent is applied onto the dielectric oxide film, dried, polyaniline film Then, the polyaniline film is treated with a dope solution in which a protonic acid and an oxidizing agent are dissolved, and the protonic acid anion of the protonic acid salt is doped into the polyaniline film to make the polyaniline film conductive. Is characterized by.

In the present invention, as the film-forming metal,
Generally, aluminum or tantalum is used,
If necessary, other metal or alloy composites can be used. A dielectric film is formed on such a film-forming metal to form an anode body of an electrolytic capacitor.

Polyaniline used in [0012] The present invention consists imino -p- phenylene structural unit represented by the general formula (I), an organic polymer soluble in a solvent in the undoped state. In particular, the polyaniline used in the present invention preferably has an intrinsic viscosity [η] of 0.40 dl / g or more measured at 30 ° C. in N-methylpyrrolidone.

Such a solvent-soluble polyaniline is
As described in detail in JP-A-3-52929, the general formula (II)

[0014]

[Chemical 3]

(In the formula, m and n respectively represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, m +
n = 1. ) Is an organic polymer having a quinonediimine structural unit and a phenylenediamine structural unit as main repeating units, and is obtained by reducing an organic polymer soluble in an organic solvent in a dedoped state with a reducing agent. be able to.

Examples of the reducing agent include phenylhydrazine, hydrazine, hydrazine hydrate, hydrazine sulfate,
Hydrazine compounds such as hydrazine hydrochloride and reductive metal hydride compounds such as lithium aluminum hydride and lithium borohydride are preferably used. Hydrazine hydrate or phenylhydrazine is particularly preferably used as the reducing agent because it does not produce a residue after the reduction reaction.

In the method for manufacturing a solid electrolytic capacitor according to the present invention, first, the imino-p thus obtained is obtained.
-A solution composition prepared by dissolving phenylene type polyaniline and a proton acid salt in an organic solvent is applied on the dielectric oxide film to form a polyaniline film.

Here, as the protonic acid salt in the solution composition, an organic acid salt having an acid dissociation constant pKa value of 4.8 or less is preferably used. Such salts of organic acids include salts of mono- or polybasic acids such as aliphatic, aromatic, araliphatic and alicyclic. Such an organic acid may have a hydroxyl group, a halogen, a nitro group, a cyano group, an amino group or the like. Therefore, as a specific example of such an organic acid,
For example, acetic acid, n-butyric acid, pentadecafluorooctanoic acid, pentafluoroacetic acid, trifluoroacetic acid, trichloroacetic acid, dichloroacetic acid, monofluoroacetic acid, monobromoacetic acid, monochloroacetic acid, cyanoacetic acid, acetylacetic acid, nitroacetic acid, triphenylacetic acid, Formic acid, oxalic acid, benzoic acid, m-bromobenzoic acid, p-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, o-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 3,5- Dinitrobenzoic acid, picric acid, o-chlorobenzoic acid, p-nitrobenzoic acid, m-nitrobenzoic acid, trimethylbenzoic acid, p-
Cyanobenzoic acid, m-cyanobenzoic acid, thymol blue, salicylic acid, 5-aminosalicylic acid, o-methoxybenzoic acid, 1,6-dinitro-4-chlorophenol, 2,
6-dinitrophenol, 2,4-dinitrophenol,
p-oxybenzoic acid, bromophenol blue, mandelic acid, phthalic acid, isophthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, α
-Alanine, β-alanine, glycine, glycolic acid,
Thioglycolic acid, ethylenediamine-N, N'-diacetic acid,
Examples thereof include ethylenediamine-N, N, N ', N'-tetraacetic acid.

Further, the organic acid may have a sulfonic acid or a sulfuric acid group. Examples of such an organic acid include, for example, aminonaphthol sulfonic acid, methanilic acid, sulfanilic acid, allyl sulfonic acid, lauryl sulfuric acid, xylene sulfonic acid, chlorobenzene sulfonic acid,
1-propanesulfonic acid, 1-butanesulfonic acid, 1-
Hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-dodecanesulfonic acid, benzenesulfonic acid, styrenesulfonic acid, p-toluenesulfonic acid,
Naphthalenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecyl Benzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, diethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, dibutylbenzenesulfonic acid, methylnaphthalenesulfonic acid, ethylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, Butylnaphthalenesulfonic acid, Pentylnaphthalenesulfonic acid, Hexylnaphthalenesulfonic acid,
Heptylnaphthalenesulfonic acid, octylnaphthalenesulfonic acid, nonylnaphthalenesulfonic acid, decylnaphthalenesulfonic acid, undecylnaphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, pentadecylnaphthalenesulfonic acid, octadecylnaphthalenesulfonic acid, dimethylnaphthalenesulfonic acid, diethylnaphthalenesulfone Acid, dipropyl naphthalene sulfonic acid, dibutyl naphthalene sulfonic acid, dipentyl naphthalene sulfonic acid,
Dihexylnaphthalenesulfonic acid, diheptylnaphthalenesulfonic acid, dioctylnaphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, trimethylnaphthalenesulfonic acid, triethylnaphthalenesulfonic acid, tripropylnaphthalenesulfonic acid, tributylnaphthalenesulfonic acid, camphorsulfonic acid, acrylamide- Examples thereof include t-butyl sulfonic acid.

Particularly, the proton acid salt which can be preferably used in the present invention is a salt of a polyfunctional organic sulfonic acid having two or more sulfonic acid groups in the molecule. Examples of such polyfunctional organic sulfonic acids include ethanedisulfonic acid, propanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, hexanedisulfonic acid, heptanedisulfonic acid, octanedisulfonic acid, nonanedisulfonic acid, decanedisulfonic acid, benzene. Disulfonic acid, naphthalene disulfonic acid, toluene disulfonic acid,
Ethylbenzenedisulfonic acid, propylbenzenedisulfonic acid, butylbenzenedisulfonic acid, dimethylbenzenedisulfonic acid, diethylbenzenedisulfonic acid, dipropylbenzenedisulfonic acid, dibutylbenzenedisulfonic acid, methylnaphthalenedisulfonic acid, ethylnaphthalenedisulfonic acid, propylnaphthalenedisulfonic acid,
Butylnaphthalenedisulfonic acid, Pentylnaphthalenedisulfonic acid, Hexylnaphthalenedisulfonic acid, Heptylnaphthalenedisulfonic acid, Octylnaphthalenedisulfonic acid, Nonylnaphthalenedisulfonic acid, Dimethylnaphthalenedisulfonic acid, Diethylnaphthalenedisulfonic acid, Dipropylnaphthalenedisulfonic acid, Dibutylnaphthalenedisulfonic acid , Naphthalene trisulfonic acid, naphthalene tetrasulfonic acid, anthracene disulfonic acid,
Anthraquinone disulfonic acid, phenanthrene disulfonic acid, fluorenone disulfonic acid, carbazole disulfonic acid, diphenylmethane disulfonic acid, biphenyl disulfonic acid, terphenyl disulfonic acid, terphenyl trisulfonic acid, naphthalene sulfonic acid-formalin condensate, phenanthrene sulfonic acid- Formalin condensate,
Examples thereof include anthracene sulfonic acid-formalin condensate, fluorene sulfonic acid-formalin condensate, and carbazole sulfonic acid-formalin condensate. The position of the sulfonic acid group in the aromatic ring is arbitrary.

Further, the organic acid salt used in the present invention is
It may be a salt of a polymeric acid. Examples of such a polymer acid include polyvinyl sulfonic acid, polyvinyl sulfuric acid, polystyrene sulfonic acid, sulfonated styrene-
Butadiene copolymer, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid, polyhalogenated acrylic acid, polyisoprene sulfonic acid, N-sulfoalkylated polyaniline, nuclear sulfonation Examples thereof include polyaniline. A fluorine-containing polymer known as Nafion (registered trademark of Du Pont, USA) is also preferably used as the polymer acid.

In the present invention, aromatic polyvalent sulfonates such as 1,5-naphthalenedisulfonate and polymer salts give conductive polyaniline excellent in heat resistance and water resistance. It is preferably used.

In the present invention, the counter ion for forming the proton acid salt may be an alkali metal ion such as sodium or potassium, an ammonium ion, or a cation from an organic amine (organic ammonium. Such salts are sometimes called organic amine salts.)
And so on. That is, the proton acid salt used in the present invention is an ammonium salt, an organic amine salt or a metal salt.

Examples of the organic amine for forming such an organic amine salt include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine and di-n.
-Propylamine, isopropylamine, diisopropylamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine,
Iminobispropylamine, methyliminobispropylamine, 3- (dibutylamino) propylamine, n-
Butylamine, di-n-butylamine, tri-n-butylamine, secondary butylamine, tertiary butylamine,
Isobutylamine, diisobutylamine, n-amylamine, isoamylamine, di-n-amylamine, tri-n-amylamine, n-hexylamine, di-n-hexylamine, trihexylamine, 2-ethylbutylamine, aminoheptane, di -N-heptylamine, octylamine, 2-aminooctane, 2-ethylhexylamine, dioctylamine, di (2-ethylhexyl) amine, trioctylamine, nonylamine, decylamine, laurylamine, octadecylamine, monoallylamine, diallylamine, triethylamine. Allylamine, cyclohexylamine, dicyclohexylamine, N, N-
Dimethyl-N-cyclohexylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, dimethylbenzylamine, ethylenediamine, N, N-diethylethylenediamine, tetramethylethylenediamine, 1 , 2-propanediamine, trimethylhexamethylenediamine, pentamethylenediamine, diethylenetriamine, N- (hydroxyethyl) diethylenetriamine, N- (cyanoethyl) diethylenetriamine, triethylenetetramine,
Tetraethylenepentamine, polyoxypropylenepolyamine, isophoronediamine, monoethanolamine,
Diethanolamine, triethanolamine, 3-amino-1-propanol, isopropanolamine, triisopropanolamine, 2-methylaminoethanol, dimethylethanolamine, 2-ethylaminoethanol, diethylethanolamine, 2-aminoethylethanolamine, N- Butyldiethanolamine, 2
-Dibutylaminoethanol, N-methyl-2,2'-iminodiethanol, 1,3-bis (aminomethyl) cyclohexanehexane, 2,4'-diphenyldiamine and the like can be mentioned.

The equivalent molar ratio of protonic acid salt / polyaniline is appropriately selected, but is usually in the range of 0.05 to 1.0, preferably in the range of 0.1 to 0.5. If the equivalent molar ratio of protonate / polyaniline is too small,
If high conductivity cannot be obtained, on the other hand, if it is too large, the mechanical strength of the obtained polyaniline film may be poor.

In the present invention, as the solvent for preparing the solution composition, for example, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide and the like are preferably used. ,However,
It is not necessarily limited to these. The concentration of polyaniline in the solution composition is usually 2 to 15
The concentration of the proton acid salt ranges from 1 to 24% by weight.
It is in the range of weight percent, but is not necessarily limited to these.

According to the method of the present invention, a dielectric film is first formed on the above-mentioned film-forming metal, and then the solution composition containing the polyaniline and the proton acid salt is used to form the dielectric film. A film made of polyaniline is formed on the film. Specifically, a polyaniline solution containing a protonic acid salt as described above is applied on the dielectric film, or the derivative is immersed in the polyaniline solution under normal pressure or under vacuum, and then heated under normal pressure or under vacuum. Then, the solution composition is dried to form a film. Although these solution compositions and the film formed from them contain the above-mentioned protonic acid salt, there seems to be no electrostatic interaction between the polyaniline and the anion of the protonic acid salt, and polyaniline is undoped. It is in a state and has no conductivity.

Next, according to the method of the present invention, such a polyaniline film is subjected to oxidation and doping treatment with a solution in which a protonic acid and an oxidizing agent are dissolved (hereinafter sometimes referred to as a dope solution). Therefore, conductivity can be imparted to polyaniline. The protonic acid used for this oxidation and doping treatment preferably has a low pKa value and a large molecular size. Those with small molecular size are
This is because the protonic acid itself is doped and the protonic acid anion portion of the proton acid salt in polyaniline does not occur. Specifically, 1,5-naphthalenedisulfonic acid, m-benzenedisulfonic acid, polystyrenesulfonic acid and the like are preferably used. A method using the same protonic acid as the proton acid salt in polyaniline is also preferably used.

The oxidizing agent used in the method of the present invention is preferably an oxidizing agent itself or an oxidizing agent in which the reduced product after the oxidation reaction is difficult to be doped into polyaniline, and more preferably, it is soluble in a suitable solvent. It is an oxidant.
Specific examples of such an oxidizing agent include p-benzoquinone, o-benzoquinone, p-toluquinone and oxy-p-.
Quinone-based oxidizers such as benzoquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, diphenoquinone, stilbenequinone and 2,3-dichloro-5,6-dicyanobenzoquinone, and 2,5-dimethylhexane-2,5- Dihydroxyperoxide, cumene hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-
Hydroperoxide-based oxidizing agents such as tetramethylbutyl hydroperoxide, hydrogen peroxide, oxime-based oxidizing agents such as p-quinonedioxime, thiuram-based compounds such as tetramethylthiuram monosulfide,
Examples thereof include sulfenamide compounds such as cyclohexylbenzothiazyl sulfenamide.

As the solvent for the dope solution, water or an appropriate organic solvent or a mixture thereof is usually used. The composition of the dope solution depends on the temperature of the doping treatment and the thickness of the formed polyaniline film, but normally, the concentration of the protonic acid in the dope solution is preferably in the range of 5 to 30% by weight, and the concentration of the oxidant is Is preferably in the range of 0.5 to 30% by weight. In order to dope the polyaniline film, the polyaniline film is contacted with the dope solution by a method of immersing the polyaniline film in the dope solution as described above, a method of applying the dope solution to the polyaniline film, or a method of spraying the dope solution. You can do it all the time.

The temperature of this doping process is usually 15
The temperature is in the range of up to 60 ° C., but if necessary, the doping process can be performed at a higher temperature to shorten the required time.
However, if the temperature is too high, the mechanical strength of the polyaniline film may be deteriorated, which is not preferable.

As described above, after the polyaniline film is formed on the dielectric film, the polyaniline is doped by bringing it into contact with the above-mentioned dope solution. In the present invention, in this doping process,
In fact, as a dopant, it contributes to making polyaniline conductive by interacting with it.
It may be the anion of the proton acid salt first contained in the solution composition, the anion of the proton acid used in the dope solution, or both of them. According to the present invention, which is contributed by selecting the molecular size and polarity of each anion used,
You can control it freely.

According to the method of the present invention, the polyaniline film can be easily doped with a dopant having a large molecular size, and the doping rate is dramatically improved. This means that when an electron is removed from the unshared electron pair of the imino nitrogen of the reduced polyaniline moiety by the oxidant, a cation radical called a semiquinone radical is generated, a charge site is generated, and an electrostatic field is formed. It is considered that the anion of the dopant easily interacts with the polyaniline by the electrostatic force.
On the other hand, in the protonic acid doping of the quinonediimine structural portion, such electrostatic interaction does not work,
It is believed that the protonic acid doping is slow because it depends only on the diffusion of the protic acid.

After such a doping process, the polyaniline film is washed with a solvent such as ethanol and dried. Next, after mounting the terminals on the polyaniline film using a conductive paste such as carbon or silver, the terminals are mounted with an appropriate resin such as an epoxy resin, and subjected to aging treatment.
Obtain a solid electrolytic capacitor.

[0035]

As described above, according to the method of the present invention,
Since the polyaniline film formed on the dielectric film can be subjected to the doping treatment in a short time, and in this doping treatment, the dopant that interacts with the polyaniline can be freely selected without any restriction such as the molecular size. A solid electrolytic capacitor having excellent durability can be obtained. Further, such a solid electrolytic capacitor according to the present invention can improve capacitor characteristics such as reduction of high frequency impedance as compared with a conventional electrolytic capacitor using an electrolyte solution or manganese dioxide.

Further, a polyaniline film containing no protonic acid salt is formed and then immersed in a protonic acid solution,
Since the time required for the doping process can be significantly shortened as compared with the method of performing the doping process, the manufacturing efficiency of the capacitor can be improved.

[0037]

The present invention will be described below with reference to reference examples and examples, but the present invention is not limited to these.

Reference Example 1 (Production of quinonediimine / phenylenediamine type conductive polyaniline in a doped state by oxidative polymerization of aniline)
In a 10-liter separable flask equipped with a stirrer, a thermometer and a straight pipe adapter, 6000 g of distilled water, 3
360 ml of 6% hydrochloric acid and 400 g (4.295 mol) of aniline were charged in this order to dissolve the aniline. Separately, while cooling with ice water, distilled water 149 in a beaker
Add 434 g (4.295 mol) of 97% concentrated sulfuric acid to 3 g,
A sulfuric acid aqueous solution was prepared by mixing. This sulfuric acid aqueous solution was added to the separable flask, and the entire flask was cooled to -4 ° C in a low temperature constant temperature bath.

Next, 980 g (4.295 mol) of ammonium peroxodisulfate was added to 2293 g of distilled water in a beaker and dissolved to prepare an oxidizing agent aqueous solution. The entire flask was cooled in a low temperature constant temperature bath, while maintaining the temperature of the reaction mixture at -3 ° C or lower, while stirring, to an acidic aqueous solution of aniline salt, using a tubing pump, using a straight pipe adapter, the above ammonium peroxodisulfate aqueous solution. 1 ml
The mixture was gradually added dropwise at a rate of not more than / minute. Initially, the colorless and transparent solution changes from green-blue to black-green as the polymerization proceeds,
Then, a black-green powder was deposited.

Although a temperature rise was observed in the reaction mixture at the time of this powder deposition, the temperature in the reaction system was cooled to -3 by cooling.
The temperature was kept below ℃. After the powder is deposited, the dropping rate of the aqueous ammonium peroxodisulfate solution may be slightly increased, for example, about 8 ml / min. However, also in this case, it is necessary to monitor the temperature of the reaction mixture and adjust the dropping rate so as to maintain the temperature at −3 ° C. or lower. Thus, after the dropping of the aqueous ammonium peroxodisulfate solution was completed over 7 hours, the stirring was continued for another 1 hour at a temperature of -3 ° C or lower.

The obtained polymer powder was filtered off, washed with water, washed with acetone, and vacuum dried at room temperature to obtain a black-green quinonediimine / phenylenediamine type conductive polyaniline powder 4.
30 g was obtained. This was pressure-molded into a disk having a diameter of 13 mm and a thickness of 700 μm, and by the van der Pauw method,
The conductivity was measured and found to be 14 S / cm.

(Production of Quinonediimine / Phenylenediamine Type Solvent-Soluble Polyaniline by Dedoping of Conductive Organic Polymer) 350 g of the above-mentioned doped conductive polyaniline powder was added to 4 liters of 2N ammonia water and rotated by an auto-homomixer. 5 at several 5000 rpm
Stir for hours. The mixture changed from black green to blue purple.

The powder was filtered off with a Buchner funnel, washed repeatedly with distilled water while stirring in a beaker until the filtrate became neutral, and then washed with acetone until the filtrate became colorless. did. Then, the powder was vacuum dried at room temperature for 10 hours to obtain 280 g of a dark brown dedoped solvent-soluble quinonediimine / phenylenediamine type polyaniline powder. This polyaniline is N-methyl-2-
Soluble in pyrrolidone, the solubility is 100g of the same solvent
To 8 g (7.4%). The intrinsic viscosity [η] measured at 30 ° C. using this as a solvent was 1.23.

EXAMPLE 1 Aluminum (thickness 70 μm, area 1 cm ² ) whose surface was roughened by etching was used as a film-forming metal, and this was subjected to direct current in a 3 wt% ammonium adipate aqueous solution at about 70 ° C. A voltage of 50 V was applied to form an insulating film (dielectric film) made of aluminum oxide, which was used as the anode body of the capacitor.

1.8 g of phenylhydrazine was dissolved in 106.2 g of N-methyl-2-pyrrolidone, and 12.0 g of the solvent-soluble quinone diimine / phenylenediamine type polyaniline prepared in the above Reference Example was dissolved in this solution.
An imino-p-phenylene type polyaniline solution was prepared. Next, 7.2 g of polyvinylsulfonic acid and 12.3 g of triethylamine were dissolved in 60.5 g of N-methyl-2-pyrrolidone. To 80 g of the obtained polyvinyl sulfonic acid triethylamine salt solution, 120 g of the imino-p-phenylene type polyaniline solution was added, stirred and mixed to obtain an organic polymer composition solution containing polyaniline and a proton acid salt.

The capacitor anode body was dipped in the organic polymer composition solution and then dried by heating in a hot air circulation dryer at about 150 ° C. for 30 minutes to form a polyaniline film on the anode body. A capacitor anode body obtained by laminating the polyaniline film thus obtained was used as polyvinyl sulfonic acid 10
It was immersed in an ethanol / water mixed solution containing 40% by weight and 2.5% by weight of p-benzoquinone at about 40 ° C. for 60 minutes, washed with ethanol, and dried at 60 ° C. for 20 minutes. Then, a conductive paste was applied and a cathode lead was attached.
Table 1 shows the capacitor characteristics of the element thus obtained.

Example 2 1.8 g of phenylhydrazine was dissolved in 106.2 g of N-methyl-2-pyrrolidone, and 12.0 g of the solvent-soluble quinone diimine / phenylenediamine type polyaniline prepared in the above Reference Example was dissolved in this solution. Let me imino-p-
A phenylene type polyaniline solution was prepared.

Next, N-methyl-2-pyrrolidone 71.7
4.8 g of 1,5-naphthalenedisulfonic acid and 3.5 g of diethanolamine were dissolved in g. 120 g of the 1,5-naphthalenedisulfonic acid diethanolamine salt solution thus obtained was added with 120 g of the imino-p-phenylene type polyaniline solution.
Was added, stirred and mixed to obtain an organic polymer composition solution containing polyaniline and a proton acid salt.

After dipping the same anode body as in Example 1 into the above organic polymer composition solution as in Example 1, about 1
It was heated and dried for 30 minutes in a hot air circulation dryer at 50 ° C. to form a polyaniline film on the anode body. A capacitor anode body in which the polyaniline film thus obtained is laminated
After dipping in an ethanol / water mixed solution containing 10% by weight of 1,5-naphthalenedisulfonic acid and 2.5% by weight of p-benzoquinone at about 40 ° C. for 60 minutes, washed with ethanol, 6
It was dried at 0 ° C. for 20 minutes. Then, in the same manner as in Example 1, the conductive paste was applied and the cathode lead was attached. Table 1 shows the capacitor characteristics of the element thus obtained.

Example 3 As the film forming metal, a porous sintered body having a volume of 20.8 mm ³ obtained by sintering fine powder of tantalum was used, and 0.1% by weight at 85 ° C.
A direct current voltage of 30 V was applied in a phosphoric acid aqueous solution to form an insulating film (dielectric film) made of tantalum oxide on the surface of the porous sintered body, and used as an anode body of a capacitor.

1.8 g of phenylhydrazine was dissolved in 106.2 g of N-methyl-2-pyrrolidone, and 12.0 g of the solvent-soluble quinone diimine / phenylenediamine type polyaniline prepared in the above Reference Example was dissolved in this solution.
An imino-p-phenylene type polyaniline solution was prepared. Next, 7.2 g of polyvinylsulfonic acid and 12.3 g of triethylamine were dissolved in 60.5 g of N-methyl-2-pyrrolidone. To 80 g of the obtained polyvinyl sulfonic acid triethylamine salt solution, 120 g of the imino-p-phenylene type polyaniline solution was added, stirred and mixed to obtain an organic polymer composition solution containing polyaniline and a proton acid salt.

The capacitor anode body was dipped in the organic polymer composition solution and then dried by heating in a hot air circulation dryer at about 150 ° C. for 30 minutes to form a polyaniline film on the anode body. The capacitor anode body laminated with the polyaniline film thus obtained was immersed in an ethanol / water mixed solution containing 10% by weight of 1,5-naphthalenedisulfonic acid and 2.5% by weight of p-benzoquinone at about 40 ° C. for 60 minutes. After the immersion, it was washed with ethanol and dried at 60 ° C. for 20 minutes. Then, a conductive paste was applied and a cathode lead was attached. Table 1 shows the capacitor characteristics of the element thus obtained.

Example 4 1.8 g of phenylhydrazine was dissolved in 106.2 g of N-methyl-2-pyrrolidone, and 12.0 g of the solvent-soluble quinone diimine / phenylenediamine type polyaniline prepared in the above Reference Example was dissolved in this solution. Let me imino-p-
A phenylene type polyaniline solution was prepared.

Next, N-methyl-2-pyrrolidone 60.5
7.2 g of polyvinylsulfonic acid and 1 of triethylamine
2.3 g was dissolved. To 80 g of the obtained polyvinyl sulfonic acid triethylamine salt solution, 120 g of the imino-p-phenylene type polyaniline solution was added, stirred and mixed to obtain an organic polymer composition solution containing polyaniline and a proton acid salt.

The same anode body as in Example 3 was immersed in the above organic polymer composition solution in the same manner as in Example 1, and then about 1
It was heated and dried for 30 minutes in a hot air circulation dryer at 50 ° C. to form a polyaniline film on the anode body. A capacitor anode body in which the polyaniline film thus obtained is laminated
After dipping in an n-propyl alcohol / water mixed solution containing 10% by weight of 1,5-naphthalenedisulfonic acid and 0.63% by weight of p-quinone oxime at about 60 ° C for 120 minutes, washed with ethanol and then at 60 ° C. Allowed to dry for 20 minutes. Thereafter, the conductive paste is applied in the same manner as in Example 1,
The cathode lead was attached. Table 1 shows the capacitor characteristics of the element thus obtained.

Comparative Example 1 Aluminum was placed as a cathode body on the same capacitor anode body as in Example 1 and separator paper was placed between the anode body and this, and this was mixed with 5% by weight of ammonium adipate in water / ethylene glycol. The separator paper was dipped in the solution to impregnate the solution with the solution. Terminals were drawn from both the anode and cathode aluminum. Table 1 shows the capacitor characteristics of the element thus obtained.

Comparative Example 2 The same capacitor anode body as in Example 3 was impregnated with an aqueous solution of manganese nitrate, and then a manganese dioxide layer was formed as a solid electrolyte by thermal decomposition treatment. Furthermore, after re-forming, electrode terminals were attached with a conductive paste. Table 1 shows the capacitor characteristics of the element thus obtained.

[0058]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuhito Funada 1-2 1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Masao Abe 1-1 1-1 Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Co., Ltd. (56) Reference JP-A-3-285983 (JP, A) JP-A-5-3138 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) ) H01G 9/02

Claims (2)

(57) [Claims] 1. A method for producing a solid electrolytic capacitor, comprising a dielectric oxide film formed on a film-forming metal, and a film comprising a conductive organic polymer composition containing polyaniline as a solid electrolyte formed on the dielectric oxide film. , The general formula (I): In represented by imino -p- phenylene structural unit Tona
Ri, a solution composition comprising polyaniline and protonic acid salt which is soluble in an organic solvent is applied onto the dielectric oxide coating, dried, and polyaniline film, then the the polyaniline film with a protonic acid oxidizing agent It was treated with a dope prepared by dissolving a protonic acid anions of the proton acid salt doped into the polyaniline film, method of manufacturing a solid electrolytic capacitor, characterized in that the conductive polyaniline film. 2. A polyaniline soluble in an organic solvent is N
The method for producing a solid electrolytic capacitor according to claim 1, wherein the intrinsic viscosity [η] measured in methyl-2-pyrrolidone at 30 ° C. is 0.40 dl / g or more.